Intracranial pressure (ICP) is an extremely important determinant of brain function, and its monitoring is central to the management of patients who suffer from a variety of brain diseases and disorders. Successful monitoring and treatment of elevated ICP has been shown to be an important determinant of patient outcome in a variety of clinical settings. Unmanaged ICP often results in the death of the patient. At present, ICP can only be measured by performing a neurosurgical procedure in which a hole is drilled into the skull and a transducer or catheter is inserted into one of a variety of places within the cranium. Besides the risks attendant with this procedure, measurements of ICP can only be performed in hospitals staffed by neurosurgeons. A simple non-invasive method of monitoring ICP (nICP) would allow measurement of this critical parameter in all patients at risk of developing increased ICP, both in and outside of the hospital setting, with or without an attending neurosurgeon. We have developed a general strategy for determining nICP based on novel analysis of standard diagnostic ultrasound applied to the brain and invasively and continually monitored arterial blood pressure. We have designed a specific algorithm based on this strategy, assembled a prototype device that implements this algorithm, and tested the algorithm successfully on ten out of eleven patients whose mean ICP ranged between 7-25 mmHg. Finally, we have corralled the appropriate intellectual property and have formed a company that is ready to carry this work forward into the clinic and beyond. We have two goals for this proposal. The first goal of this proposal is to further test our prototype device and algorithm on humans to verify and extend the feasibility of this approach to determining nICP. The second goal is to replace the need for invasively measured, continuous arterial blood pressure in our existing algorithm with non-invasively measured, continuous arterial blood pressure.